TOAST outsides of rolls on griddle, grill or in oven until warmed and lightly browned on both sides.
FOR each serving: Spread 1 Tbsp. bistro sauce onto bottom half of roll. Fill wth 2 lettuce leaves, 2 tomato slices and 1/2 cup oysters. Spoon about 3 Tbsp. of the remaining bistro sauce into 1-oz. cup. Serve with sandwich. Garnish with lemon wedge.